Detection and Measurement of the Disulfide WR33278 [NH₂(CH₂)₃NHCH₂CH₂S-]₂ in Blood and Tissues

Abstract

A liquid chromatographic method employing an in-series dual mercury/gold amalgam electrochemical detector has been developed for measurement of the symmetrical disulfide metabolite WR33278 [NH₂(CH₂) ₃NHCH₂CH₂S-]₂ of the radioprotector WR2721 in blood, tissues and biological fluids such as urine. The problem of adsorption of this disulfide to the octylsilane reverse phase column was overcome by including 10.7 mmol/L ethylamine in the mobile phase. The retention times for WR33278 and WR183159 [CH₃NH (CH₂) ₃NHCH₂CH₂S-]₂, the internal standard, are approximately 3.9 and 11 minutes, respectively. Linearity of the method was to 1000 umol/L. This method has good precision and accuracy and has a sensitivity limit of 0.2 umol/L. Investigation of the metabolism and pharmacokinetics of WR33278 in patients and experimental animal models, after administration of WR2721, using the described chromatographic conditions is currently underway.